Terminal crimping machine pitch adjustment



Aug. 27, 1968 B. E. OLSSON TERMINAL CRIMPING MACHINE PITCH ADJU STM ENT Filed July 22. 1966 United States Patent 0 3,398,568 TERMINAL CRIMPING MACHINE PITCH ADJUSTMENT Billy E. Olsson, New Cumberland, Pa., assignor to Vaco Products Company, a corporation of Illinois Filed July 22, 1966, Ser. No. 567,240 7 Claims. (Cl. 72-421) This invention realtes to a feeding mechanism for advancing a strip terminal array to index the same in predetermined steps through a crimping station at which an electrical conductor is to be secured within each terminal of the array. More particularly, the invention is concerned with a pitch determining means which is adjust able to accurately select and maintain any prescribed step pitch.

Crimping machines for strip terminal arrays are now commonly employed for applying the terminals to in sulated electrical conductors. Such machines commonly include a crimping station having a ram operated plunger carrying a work head that mounts a pair of punches for folding the terminal about the conductor.

Automatic feeding mechanism is provided to regulate step-by-step advancement of the strip terminal array to assure accurate registery of each terminal at the crimping station. The feeding mechanism is normally arranged to be driven in synchronous relation by the reciprocating movement of the plunger.

It is desirable to provide a feeding mechanism which reliably maintains the prescribed feed step pitch distance during continuous high speed operation. Normally, each crimping machine is intended to 'be sufliciently versatile to handle a variety of different strip terminal arrays and this in turn requires that the feeding mechanism be easily adjustable to operate at a number of different feed step pitch distances.

In accordance with the present invention, a feeding mechanism is provided to be driven in response to the plunger movement. The feeding mechanism may include a conventional type of feed pawl located for engaging the strip terminal array and mounted upon a conventional rotary shaft for indexing the advance of the strip termi nal array in accordance with the oscillating movement imparted through the shaft. In the crimping machine illustrated herein, pitch determining means is reversibly responsive to the plunger travel and is rotatably drivingly engaged to oscillate the shaft. The pitch determining means comprises a spacer element of a selected size determined by the desired pitch distance and a pair of cam blocks flanking the spacer element in abutting relation thereto and presenting free cam faces spaced apart in accordance with the size of the spacer element and positioned to be alternately engaged during reciprocating plunger travel to generate the oscillating movement of the rotary shaft.

The cam blocks are arcuately adjustably carried on a mounting element which removably receives any one of a number of spacer elements of various different sizes. Each different size spacer element uniquely determines the positions of the cam faces to establish a series of selectable pitch distances. The mounting element is in the form of a disc rotatably drivingly engaged in co-axial relation upon the rotary shaft and it carries the spacer and the cam blocks in a symmetrical relationship.

In operation, when the plunger is down, the cam face on one of the blocks is engaged and the pawl is held at its start position in feeding relation to a strip terminal array. On upward plunger travel, the cam face on the other block is impacted to drive the pitch determining mechanism for advancing the pawl through its feed travel as determined by the travel imparted to the impacted cam block. Upon downward crimping movement of the plunger, the cam face on the first block is impacted to reverse 3,398,568 Patented Aug. 27, 1968 the pitch determining mechanism and retract the pawl to its start position. To prevent over-travel of the pawl in each direction of movement as might be occasioned by the impact conditions occurring during plunger travel, positive stop means are provided to determine the opposite extremes of movement.

Other features and advantages of the invention will be apparent from the following descritpion and claims, and are illustrated in the accompanying drawings which show an illustrative embodiment of the present invention.

In the accompanying drawings forming a part of the specification, and in which like numerals are employed to designate like parts throughout the same,

FIG. 1 is a fragmentary front elevational view of crimping machine having a feed mechanism equipped with pitch determining means constructed in accordance with this invention, the feed pawl here being illustrated in its advance position in full lines and in its start position in dotted lines;

FIG. 2 is a fragmentary rear elevational view showing the pitch determining means held in its advance position when the plunger is up; and

FIG. 3 is a developed cross sectional view taken substantially along the line 33 of FIG. 2.

Referring now to the drawings, a crimping machine, as designated generally at 10 in FIGS. 1 and 2, is shown herein for facilitating disclosure of the advantages and operation of the pitch determining mechanism of this invention. The crimping machine has a rigid framing structure including a base 11, an upstanding support wall 12 and vertical tracks 13 carried on the wall 12. A Work head 14 is guided in the tracks 13 and carries a set of crimping punches indicated generally at 15. The head 14 is carried by a ram operated plunger 16 that is vertically reciprocable for powering the crimping punches. An adjustable control mechanism 17 is provided for regulating the punch travel imparted by the plunger. This structure maybe of any conventional type.

The upstanding support wall 12 also mounts a feeding mechanism designated generally at 18 for guiding a strip terminal array which is to be located in the usual guideway G provided in the base 11. As is conventional, the feeding mechanism 18 includes a rotary shaft 19 journaled in the support wall and carrying a feed pawl 20 to engage the strip terminal array and move from the dotted line start position illustrated in FIG. 1 to the full line advance position illustrated in FIG. 1 for imparting a prescribed feed pitch distance that insures arrival of each terminal in accurately positioned relation to the crimping punches at the crimping station.

In the embodiment illustrated herein, the rotary shaft 19 projects fore and aft of the support wall 12 and at its forward end carries a driver disc 21 (FIG. 3) in splined relation. A pawl support arm 22 is journaled on a hub portion of the driver disc 21 and is retained by a washer 22W and a cap screw 22C. The pawl support arm 22 has a set of three arcuate slots 22S and is fixed at any position within the rotary range accommodated by a set of three cap screws 23 passing through these slots 22S and anchored to the driver disc 21. The lower end of the pawl support arm 22 carries a horizontal mounting axle 24 on which the pawel 20 is journaled, with a torsion spring 25 encircling this axle and having one end 25A anchored to the pawl support arm 22 and the other end 258 engaging the pawl normally to bias the pawl in a clockwise direction as viewed in FIG. 1. The pawl 20 thereby is maintained seated in a feed hole of the strip terminal array during advance movement and yieldingly cams free of the feed hole to return to start position and enter the next successive feed hole. To maintain the strip terminal array against accidental shifting during return movement of the pawl, a brake mechanism (not shown) of any suitable type may be incorporated in the crimping machine.

The feeding mechanism 18 includes a pitch determining mechanism mounted on the rear end of the rotary shaft 19 and responsive to a driver 26 which is carried by the plunger 16 to undergo to and fro vertical movement in synchronism with the plunger travel. The driver is equipped with a cam roller 27 serving as an impact element for engagement with the pitch determining means which is rotatably drivingly engaged to the shaft 19.

The pitch determining mechanism in accordance with this invention consists of a spacer element 28 and a pair of cam blocks 29, 30 flanking the spacer element in oppositely abutting relation and presenting free cam faces 29F, 30F spaced apart along the travel path of the impact cam 27 to be alternately interposed in oppositely confronting relation to the impact cam 27 during to and fro vertical movement thereof.

A compact mounting arrangement is provided for the pitch determining mechanism and includes a stationary retainer generally C-shaped and of cup-like form fixed on the rear face of the upstanding support wall 12 and serving as a guide housing that receives a mounting disc 32 which is secured on the rear end of the shaft in rotatably driving relation by means of a radial lock pin 321. The mounting disc 32, in turn, serves as a rotary force transmitting support carrying the spacer element 28 which is removably anchored by means of a mounting pin 28F and carrying the arcuate cam blocks 29, 30 which are adjustably mounted by means of slots 298, 305 and cooperating cap screws 29C, 30C.

As shown in FIG. 2, when the plunger 16 is up, the cam roller 27 engages the free face 29F of the upper cam block to determine the advanced position for the pawl 20 as represented in full lines in FIG. 1. Movement of the cam roller 27 downwardly during the crimping stroke of the plunger impacts it with the free face 30F of the lower cam block to transmit a predetermined range of rotary movement through the pitch determining mechanism for rotating the shaft 19 and retracting the pawl to its start position as represented in dotted lines in FIG. 1. Upward movement of the plunger brings the impact cam 27 against the face 29F on the upper cam block. This alternating action against the cam blocks 29, 30 repeatedly applies reversing forces to the spacer element 28 to oscillate'the rotary shaft 19 in synchronous relation to the plunger travel during successive feed cycles.

The spacer 28 serves as the pitch determining element and conveniently is in the form of a bushing, the diameter of which determines the position and spacing of the cam faces 29F, 30F on the cam blocks and thereby determines the length of the pawl travel. When the pitch bushing 28 is replaced with a smaller diameter bushing, the cam blocks 29, 30 are shifted arcuately into abutting relationship with the smaller bushing to provide a shorter travel distance for the pawl. correspondingly, when the pitch bushing is replaced with a larger diameter bushing and the cam blocks are adjusted in the opposite sense to bring the cam faces 29F, 30F closer together, the arrangement is set for a longer distance feed travel.

Where the required different pawl feed travels are known, a separate pitch bushing of appropriate diameter is provided corresponding to each specific value of feed travel and conversion of the pitch determining mechanism from one travel to another is accomplished by replacing the pitch bushing with the proper diameter element, with the cam blocks being adjusted to accommodate the new bushing in a relationship such that the cam blocks flank and oppositely abut the bushing. The anchor screws 29C, 30C are then tightened to secure the blocks against chatter during impact by the cam roller 27. It may be noted that the mounting arrangement for the pitch determining mechanism is symmetrical in that the axes of the pitch bushing and of the rotary shaft define a plane which bisects the included angle defined between the flat faces 29F, 30F of the cam blocks. These cam faces, when impacted, are driven towards a substantially vertical orientation as illustrated for the cam face in FIG. 2. The relatively high speed impact travel conditions may induce over-travel and chattering of the. cam blocks 29, 30. Positive stop means are provided for limiting any such over-travel. For this purpose, the annular wall 31W of the cup-like retainer is provided with a pair of arcuate slots 29A, 30A flanking and defining an arcuate abutment 31A which presents spaced apart abutment faces 33, 34. Each of the cam blocks 29, 30 has a radial bore mounting a stop pin 33P, 34F to operate in the corresponding retainer slot and engage the corresponding abutment face for defining the extreme of rotary movement at a position when the corresponding cam face is vertical. Thus, as is apparent in FIG. 2, upward travel of the plunger transmits clockwise rotary movement through the upper cam block 29 and through the pitch bushing 28 to rotate the shaft 19 until the stop pin 33P strikes the abutment face 33. This travel limit is selected to coincide with the true vertical orientation of the cam face 29F. Corresponding relationships are attained between the lower cam block 30 and its stop pin 34P during downward plunger travel.

It will now be apparent that the pitch determining mechanism of this invention maintains the established pitch setting in the presence of repeated impacts. The driving force is transmitted from the cam roller 27 through one or the other of the cam blocks to the pitch bushing 28 and from the pitch bushing through the mounting disc 32 to the rotary shaft 19. From this point, the travel is transmitted to the pawl 20 in the usual fashion. Adjustment is simple and accurate because the diameter of the pitch bushing determines the travel stroke and the positive stop pins 33P, 34P prevent over-travel. Minor adjustments in the touch of the pawl 20 and in its beginning and end travel points may be provided by rotating the pawl support arm 22 on the driver disc 21 as is accommodated by the slots 22S and cap screws 23.

Thus, while preferred constructional features of the invention are embodied in the structure illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

What is claimed is:

1. In feeding mechanism for advancing a strip terminal array in predetermined steps, said mechanism including meansfor moving an impact cam to and fro along a predetermined travel path, a shaft mounting a pawl to engage the strip terminal array and pitch determining means responsive to the to and fro movement of the impact cam and rotatably drivingly engaged to said shaft, the improvement wherein said pitch determining means comprises spacer means of predetermined size and a pair of cam blocks flanking said spacer means in oppositely abutting relation thereto and presenting free cam faces spaced apart to alternately assume oppositely confronting relation to the impact cam during to and fro movement thereof.

2. In feeding mechanism in accordance with claim 1 and wherein said pitch determining means includes a mounting element drivingly engaged with said shaft and carrying said spacer means in rigid relation thereon and positive stop means for limiting movement of said shaft at opposite extremes of rotary movement to prevent overtravel thereof in response to the imapct cam.

3. In feeding mechanism in accordance with claim 1 and wherein said pitch determining means includes a stationary retainer surrounding the axis of said shaft, a mounting element journaled in said retainer and drivingly engaged with said shaft, means removably mounting said spacer means in rigid relation on said mounting element, and means adjustably mounting said cam block to enable flanking abutment with various sizes of said spacer means.

4. In feeding mechanism in accordance with claim 3 and wherein said pitch determining means has abtument faces on said retainer and a spearate radial stop pin carried in each block and engageable with one of said abutment faces at the extreme travel position for such block to prevent overtravel.

5. In a strip terminal crimping machine, a base, a vertically reciprocating plunger guided on said base, an impact cam carried on said plunger to move along a vertical path, and feed mechanism including a feed pawl, a shaft rotatably mounted on said base and drivingly engaging said pawl, a mounting disc drivingly engaged with said shaft, a spacer element rigidly carried on said disc, and a pair of cam blocks adjustably mounted on said disc in oppositely abutting flanking relation to the spacer element, said cam blocks collectively presenting free cam faces spaced apart to alternately assume oppositely confronting relation to the impact cam during to and fro movement thereof.

6. In a strip terminal cirmping machine in accordance with claim 5 and wherein said shaft and said mounting disc rotate about .a common horizontal axis, said spacer element has a mid point cooperating with said axis to define a plane of symmetry and said cam blocks are arcuately arranged on said mounting disc and present flat free cam faces collectively defining an included angle that is bisected by said plane of symmetry.

7. In a strip terminal crimping machine in accordance with claim 6 and wherein said spacer element is circular.

References Cited UNITED STATES PATENTS 2,876,452 3/1959 Herman et a1. 29--203 3,004,581 10/1961 Krol et al. 29203 3,101,765 8/1963 Batcheller 29203 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,398 ,568 August 27 1968 Billy E. 0155011 It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 62, "pawel" should read pawl Column 3, line 22, after "retainer" insert 31 Column 4, line 66, "imapct" should read impact line 74, "block" should read blocks Column 5, line 2, "abtument" should read abutment line 3, "spearate" should read separate line 20, "cirmping" should read crimping Signed and sealed this 13th day of January 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents 

1. IN FEEDING MECHANISM FOR ADVANCING A STRIP TERMINAL ARRAY IN PREDETERMINED STEPS, SAID MECHANISM INCLUDING MEANS FOR MOVING AN IMPACT CAM TO AND FRO ALONG A PREDETERMINED TRAVEL PATH, A SHAFT MOUNTING A PAWL TO ENGAGE THE STRIP TERMINAL ARRAY AND PITCH DETERMINING MEANS RESPONSIVE TO THE TO AND FRO MOVEMENT OF THE IMPACT CAM AND ROTATABLY DRIVINGLY ENGAGED TO SAID SHAFT, THE IMPROVEMENT WHEREIN SAID PITCH DETERMINING MEANS COMPRISES SPACER MEANS OF PREDETERMINED SIZE AND A PAIR OF CAM BLOCKS FLANKING SAID SPACER MEANS IN OPPOSITELY ABUTTING RELATION THERETO AND PRESENTING FREE CAM FACES SPACED APART TO ALTERNATELY ASSUME OPPOSITELY CONFRONTING RELATION TO THE IMPACT CAM DURING TO AND FRO MOVEMENT THEREOF. 